From: Niklas Haas <ffmpeg@haasn.xyz>
To: ffmpeg-devel@ffmpeg.org
Cc: Niklas Haas <git@haasn.dev>
Subject: Re: [FFmpeg-devel] [PATCH] avfilter/vf_thumbnail: unroll and use multiple histograms
Date: Wed, 16 Jul 2025 10:17:52 +0200
Message-ID: <20250716101752.GD12613@haasn.xyz> (raw)
In-Reply-To: <20250712113837.307327-1-ffmpeg@haasn.xyz>
On Sat, 12 Jul 2025 13:38:37 +0200 Niklas Haas <ffmpeg@haasn.xyz> wrote:
> From: Niklas Haas <git@haasn.dev>
>
> This naive hist[p[x]]++ loop suffers badly when there are large regions of
> identical values in the image, because of store-to-load forwarding delay.
>
> Splitting up the histogram into four "parallel" histograms and processing
> them one at a time speeds things up significantly, about 40% on my end.
Merging this patch soon.
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prev parent reply other threads:[~2025-07-16 8:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-12 11:38 Niklas Haas
2025-07-16 8:17 ` Niklas Haas [this message]
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